FUDforum is a templatable forum with i18n support based on PHP and either MySQL, Oracle, PostgreSQL, or SQLite. It features a user/group management system, a multi-lingual spell checker, both flat and thread message views, a private messaging system with multi-user forwarding capabilities, poll file attachments, and much more. It is an extremely fast and scalable forum that can fulfil the needs of both small and large forum operators.

SILC (Secure Internet Live Conferencing) is a protocol which provides secure conferencing and chat services. It can be used to send any kind of messages, in addition to normal text messages, including multimedia messages like images, video, and audio stream. All messages in the SILC network are encrypted and authenticated, and messages can also be digitally signed. SILC protocol supports AES, SHA-1, SHA-2, PKCS#1, PKCS#3, X.509, OpenPGP, and is being developed in the IETF. The software is delivered as SILC Client for end users, SILC Server for system administrators, and SILC Toolkit for application developers.

Open-Xchange Server Edition is a multi-tier, small footprint solution that integrates seamlessly into customer’s architectures, enabling smooth start of operation based on services. The Open-Xchange Server Edition supports different Enterprise Linux systems like SUSE Linux Enterprise Server 10, Red Hat Enterprise Linux 5, and Debian Etch. Users are presented with a highly advanced, improved, and intuitive browser based interface that meets all their email, calendaring, tasking, contacts, and document storage requirements. Further integrations like LDAP-support or ADS are possible. It's designed for medium organizations and educational and public administrations that want to have a customizable communication solution.

CryptoHeaven offers secure email and online file sharing/storage. Its main features are secure and highly encrypted services such as group collaboration, file sharing, email, online storage, and instant messaging. It integrates multi-user based security into email, instant messaging, and file storage and sharing in one unique package. It provides real time communication for text and data transfers in a multi-user secure environment. The security and usability of CryptoHeaven is well-balanced; even the no-so-technically oriented computer users can enjoy this crypto product with very high level of encryption.

centericq is a text mode menu- and window-driven IM interface that
supports the ICQ2000, Yahoo!, AIM, IRC, MSN, Gadu-Gadu, and Jabber
protocols. It allows you to send, receive, and forward messages, URLs,
SMSes (both through the ICQ server and email gateways supported by
Mirabilis), contacts, and email express messages, and it has many other
useful features. An internal RSS reader and a LiveJournal client are
also provided.

Apache OpenMeetings is a multi-language customizable video-conferencing and collaboration system. It supports audio/video and allows you to see the desktop of any participant. It includes a whiteboard, the ability to import a variety of image formats, invitations, a moderation system, backup and language modules, private and public conference rooms, and the ability to record meetings. The project also provides integrations for Asterisk, Jira, Confluence, Moodle, Sakai, and SugarCRM, and connectors for LDAP and ADS.

Ekiga (formely known as GnomeMeeting) is a soft phone, video conferencing, and instant messenger application for use over the Internet. It supports HD sound quality and video up to DVD size and quality. It is interoperable with many other standards compliant software, hardware, and service providers as it uses both of the major telephony standards, SIP and H.323.

aGNeS is a solid BBS system from Vestris Inc. aGNeS allows threaded discussions, article searching, archiving, thread expanding and collapsing, etc. It allows to setup as many web boards as desired with totally different layout , using one CGI. The look and feel of your forum can be just whatever you like using template pages. aGNeS is web-administrable. There are tons of features and options.